Dynamo-electric machine.



No. 68l,295. Patented Aug. 27, l90l.

J. B. BLOOD.

DYNAIO ELECTRIC IAGHINE.

(Anpliwion M m. 18. 1001.

(In Iodol.)

WITNESSES IN VE N TOR fl fiim W A TTORNE Y6 m: mum puns w, mofaumm.vusummou, o. c.

UNITED STATES PATENT OFFICE.

JOIIN BALCII BLOOD, OF NEWBURYPORT, MASSACHUSETTS.

DYNAMO-ELECTRIC MACHINE.

SPECIFICATION forming part of Letters Patent No. 681 ,295, dated August27, 1901.

Application filed March 18, 1901. Serial No. 51,577. (No model-J To allwhom it may concern.-

Be it known that I, JOHN BALCH BLOOD, a citizen of the United States,residing at Newburyport, in the county of Essex and State ofMassachusetts, have invented a new and useful Dynamo-Electric Machine,of which the following is a specification.

This invention relates to dynamo-electric machines.

The object of the invention is to simplify andimprove theconstruction ofdynamo-electric machines and to render the same more elficient.

A further object is to provide means whereby the heating eifect of thecurrent in the armature-coils is reduced to a minimum.

A further object is to provide means Whereby the inductance is reducedto a minimum.

A further object is to provide means whereby the capacity and eificiencyof armaturecores are increased.

Other objects will appear more fully hereinafter.

The invention consists substantially in the construction, combination,location, and arrangement, all as will be more fully hereinafter setforth, as shown in the accompanying drawings, and finally pointed out inthe appended claims.

In the designing of dynamo-electric machines and in the practicaloperation thereof it is exceedingly advantageous to reduce to theminimum the efiects of heating in the armature-coils, as the energyconsumed in the heating of such coils is energy wasted. The general ruleis that the heating is inversely proportional to the cross-sectionalarea of the copper in the inductor wires or limbs, and consequently thegreater the cross-sectional area of the inductor sections or wires theless will be the resistance and the less will be the loss or waste ofenergy consumed in heating up the inductor wires or sections. Thereforeit is a matter of material importance in the construction ofdynamo-electric machines to provide means whereby the largest possiblecross-sectional area of inductor-section may be employed with givenconditions of size of armature, magnetic flux, current, 4850. Again, itis also exceedingly desirable and advantageous to reduce to a minimumthe inductance. The general rule is that, other things being equal, theinduct ance is inversely proportional to the circumferential distancearound or the perimeter of the inductor wires or limbs, and consequentlythe greater this circumferential distance that is, the longer theperimeter of the active limb of the inductor-sectionthe less will be theinductance. Therefore it is important and advantageous that thisperimeter or circumferential distance be as great as possible.Myinvent-ion therefore contemplates increasing the cross-sectional areaof the inductorcopper with a given crosssection of field and at the sametime increasing the circumferential distance around the activecoillimbs. These results may be accomplished in many different ways. Inthe accompanying drawings-l have shown one construction and the bestform in which I contemplate carrying my invention into practicaloperation.

Figure l is an end view of an armature-core constructed in accordancewith the principles of my invention. Fig. 2 is a similar view showingthe inductor sections or coils applied to the core. Fig. 3 is a detachedbroken view in perspective of an armature coil or section.

Reference sign A designates the armaturecore, and in carrying out myinvention I form in the peripheral surface of such core and in the usualor any convenient manner slots or seats 13 O to receive the inductorsections or coils. Instead, however, of forming these slots or groovesof uniform dimensions throughout each slot or groove B is one-half thewidth and twice the depth of the slots or grooves O, or, to state it ina diiferent way, each slot or groove 0 is twice the width and one-halfthe depth of a groove or slot B. The grooves or slots B O alternate witheach other, and the inductor sections or coils are received therein, oneleg or limb of each coil or section being received in a slot or groove Band the other leg or limb being received in a slot or groove 0, asclearly indicated in Figs. 2 and 3.

In the manner above described I am enabled to increase to a maximum thetransverse or cross-sectional area of the inductor sections or coils,thereby reducing the resistance thereof, and consequently the heatingeffect, to a minimum. I am also enabled to increase to a maximum thecircumferential distance around the active limbs of the inductor-sec-ICO tions, and hence reduce theinductancethereof to a minimum. To moreclearly illustrate, suppose the armature-core to be provided with slotsor seats of uniform dimensionsthat is, with a width b, a depth a, andthe distance between adjacent slots at. the foot or base of the tooth 0.Then the cross-sectional area of two slots will be a X b a X b or 2 andthe iron section of the core at the root of jacent slots at the foot ofthe tooth and in, the.

line of thebottom of the wide slot. Nowwith these relative dimensionsitwill be seen that the cross-sectional area. of each-slot, which ofcourse determines the cross-sectional area of the limb; or leg of theinductor-coil which is received therein, is. equal to /fii and forany-two slots will be 8 3 or 2.66, which isthirty-three per cent.greater than wherethe. slots are of. equal dimensions, as above.

shown, thus gaining in the same percentage in. the cross-sectional areaof theinductor-sec tions, and consequently reducing theresistance'and-the heating of the-coils. Moreover, the periphery of thewide slot is a .l a 4 3 s+ 4 01-1-2 8 3 and the periphery of the deepslot is 4- -l- 4. 3., both; of which measurements are greater than theco rrespending measurements of theordi-nary con-. structions.Consequently by: my invention 1 not only, secure; a,v greater. cross-.sectional area-of inductor-section, but Ialso secure the advantage ofgreater. circumferential distance around the inductor-limbs,andconsequently.alessinductance.

Thecoilsemployed for the windingsmay be.

of. the detachable counterparttype, as. indi-' cat-.odat D in Fig.3,.and Iemployone-half as manycoils as there are slots,eacl1 coilentering a .wide shallow slot at one end and a narrow and deep slot. attheother end, as clearlyindi-i cated in. dotted lines. in..Fig. 2,andin: order unit, although for the. sake of illustration of Ytheprinoiple. involved the coil is shown.- in

Fig. Bas though it were madedouble orof separate. parts.

It will be understood that myinventionv is capable of being, carriedintdpracticeWith any desired construction of armature-core,

whether. solid or laminated or otherwisewand whether, the armature. isfixed Qrrotatable.

From the foregoing.description it will be:

readily seen thatwith a. given magnetic flux and a given mductance. theheating efi'ect It.willbe undere would be greatly decreased, or with "agiven inductance and heating a much larger magnetic flux is gained, orwith a given ilux and heating effect a much less inductance is secured,and hence a much larger current can be used, thereby increasing thecapacity or output of the machine. Thus advantage may be secured inemploying a machine of less Weight for a given work to be accomplishedor a greater output or capacity is secured with the same size or weightand less heating or less speed and greater power is developed.

My invention may be carried out in machines designed for any particularuse. Thus in the case of motors for automobiles using storage batteriesfor source of current difficultyhas heretoforebeen. experienced onaccount of the highresistance of the motor,

' which prevents the flow of suflicient current at the start. to givethe requisite. torque or turning movement. Moreover, energy is con.-sumed to no useful purpose in merely heat ing the. wires, which lossofenergy results in diminishing the store of the batteries .withoutperforminguseful work. By my invention these. objections are verygreatly avoided anda greater mileage is secured by the same batterycapacity. In the case of motorseme ployed for elevated suburban, or'street'rail ways, where a large-acceleration at the start is desiredand where there are frequent stopping. and starting, the desiredaccelerationis greatly retarded by reason of the initial. G111? rentbeing used ups-in heating the coils, and also because-ofthe burning ordestruction of the armature when current sufficient to give thedesiredacceleration is initially turned on. By my invention the resistance islessened, and hence with a givendegree. of heat development greateracceleration is secured andthe dangerzof burning or destroyingthe:

. armature is avoided Again, in the caseof very small motors the spacefor the insulas tion on the inductor-coils islimited- Bymyinventiongreater roonnfor the same. size. of motor issecured, thereby permitting.0fi thc useofi proper size of wires, and hence-increasing the capacityofthemotor.

Other instances of the utility ofmy in.ven-. tion might be cited, but itis believed .that.

the foregoing is. sufficient: to emphasize. its.

Having now set forthlthe object audnature of my invention. and aconstruction embodying-the principles thereof and having ex-. plainedthe same, its-purpose, function, and model of operation, what Iclaim.asnew andv useful and of my own invention, and desire to securebyLetters Patent, is-

1. An armature-core having slots to receive the inductor-sections, theslots which receive the same inductor-section varying in dimensions fromeach other, as and for the purpose set forth.

2. An armature-core having slots to receive the inductor-sections,adjacent slots varying in dimensions from each other, a slot of onedimension adapted to receive one limb of an inductor-section and a slotof another dimension adapted to receive the limb of the sameinductor-section, as and for the purpose set forth.

3. An armature-core having slots to receive the inductor-sections, theslots which receive the same inductor-section being of the sametransverse area but of differing linear dimensions, as and for thepurpose set forth.

4. An armature core having slots to receive the inductor-sections,adjacent slots being of the same area but of differing lineardimensions, as and for the purpose set forth.

5. The combination with an armature-core having slots to receive theinductor-sections, alternate slots being of the same linear dimensionsand the dimensions of the intermediate slots diiferin g therefrom, ofinductorsections, one limb of each section being arranged in a slot ofone dimension and the other limb thereof arranged to be received in aslot of a differing dimension, as and for the purpose set forth.

6. An armature-core having slots arranged in pairs, each pair of slotsreceiving respectively the two limbs of the same inductor-section, theslots of each pair differing from each other in linear dimensions but ofthe same transverse area, as and for the purpose set forth.

7. An armature-core having slots to receive the inductor-sections, eachalternate slot being half the depth and double the width of the nextadjacent slots, as and for the purpose set forth.

8. The combination with an armature-core having slots, each alternateslot being half the depth and double the width of the next adjacentslot, of a coil or inductor section having one of the limbs thereofreceived in a slot of one dimension and the other received in a slot ofa different dimension, as and for the purpose set forth.

9. An armature-core having slots, each alternate slot being half thedepth and double the width of the next adjacent slot, in combinationwith a coil or inductor section having the active limbs thereof ofdimensions corresponding to adjacent slots of the core, as and for thepurpose set forth.

10. An armature-coil or inductor-section having one of the limbs thereofone-half the thickness and double the width of the other limb, as andfor the purpose set forth.

11. An armature coil or winding having its active limbs of the samecross-sectional area but of different linear dimensions, as and for thepurpose set forth.

12. An armature coil or winding having its active limbs of diiferingdimensions, as and for the purpose set forth.

In witness whereof I have hereunto set my hand, this 4th day of March,1901, in the presence of the subscribing witnesses.

JOHN BALOH BLOOD.

Witnesses:

JOSHUA HALE, LOUIS L. Donen.

